Valve for internal-combustion engines



Oct. l, 1929. R. E. BlssE-:LL

VALVE FOR INTERNAL COMBUSTION ENGINES Filed April 2o, 1927 Patented Oct. 1, 1929 UNITED STATES PATENT- oFFlcE RICHARD E. BISSELIa-OF'CLEVELAND HEIGHTS, OHIO, ASSIGNOR TO THOMJPSON PROD- .'UCTS, INC., A CORPORATION OF OHIO VALVE FOR INTERNAL-COMBUSTION ENGINES Application filed April 20,

This invention relates'to valves for internal combustion engines and more particularly to exhaust valves.

Such exhaust valves are subject to a high degree of heat from the hot products of combustion. This heat is dissipated largely by conduction along the'valvestem and from thence by conduction-to the guide for the valve stem and by radiation and conduction into the air around the stem.

The principal object, therefore, or" thepresent invention is to provide means for increasing the rate of flow of heat from the hot portions of the valve to cool portions, es-

pecially in hollow stem valves.

According to my invention, therefore, a member of relatively high heat conductivity. is arranged within the valve stem to aid in the conduction of heat from the head to the tail of the valve. I

As this member may be wholly enclosed within the stem the metal or alloy for making the same may be selected without regard to corrodibility. \Further, as the walls of the stem carry the strains and e stresses, the strength or hardness of such metal or alloy is likewise immaterial.

The chief requirement is a high heat conductivity. A secondary advantageous requirement is that the co-efcient of expansion by heat shall be as nearly the same as that of lthe metals-forming the valve head and stem as ossible. y'

, n the basis of heat conductivity, copper is one of the best materials for my purpose.

Aluminum and magnesium also have high heat conductivities much greater than that of steel although less than that of copper.

' l Where extreme lightness is concerned, alumi- 40 num or magnesium may be preferable to copper since, for equal weights of metal, both aluminum and magnesium conduct con-l siderably mre heat than copper.

Similarly, alloys of copper, aluminum,

- magnesium or other metals may be used for this purpose. Preferably the metal alloy should be one which will not fuse at any temperature attained by an part of the valve.

. The variations linl coe cient of thermal ex- 5 pansion between diferent metals and alloys tion will be hereinafterset forth in connec- 1927. Serial No. 185,099.

should be taken into consideration. The coefficient of heat expansion for copper is nearer that of steel than either aluminum or magneslum. Hence from the point of view of thermal expansion, copper again is to be preferred as 'it expands and contracts with heat much more nearly in accordancewith steel than either of the other metals mentioned. Provision lshould be made for variationsin thermal expansion of the steel stem of the valve and the copper or other member within v the stem. This'y may be brought about in varions ways such as providing adequate play 'laterally and longitudinally betweenv such member and the interior of the valve stem or else the member is connected at its ends only, and the member is bent intermediate its length to provide for longitudinal expansion. ther objects and features of the invention with lthe accompanying-drawings which set forth the invention in its preferred form.

On the drawings: Figure l is a longitudinal, central section through a valve constructed in accordance with the present invention. l f

Figure 2 is a detail sectional view ony an enlarged scaleof the lower end of the valve stem. y

Figure 3 is a section om the line III- III of Figure 1.

Figure fl is a longitudinal 'central section l through a further modification.

Figure 5 is a detail sectional view on a'n enlarged scale'of a still further modified form of construction.

Figure 6 is a detail sectional view on an enlarged scale ofyet another form of construction.

The form of construction shown in Figures 1,' 2 and 3 com rises a head 1 and a hollow stem 2 integra y formed therewith. Within Y the bore of theV stem i's acopper rod 3. With the parts proportioned asy shown, maki the stem hollow land inserting a co perl ro therein will increase the heat con uctivity of the central part of the stem 'While' decreasing the weight of the same part as com;

pared with a so id steel stem. 'The bord of the stem is made with restricted portions' l and 6 at the ends adapted to support the ends of the copper rod 4. Enough play is provided between the restricted portions 5 and 6 of the bore and the copper rod so that under the maximum temperature attained, the expansion of the copper with respect to the steel will not do more than close the space around the ends of the rod and thus avoid the production of any burstingl or disruptive "strains in the valve head or stem. The space left for expansion should be greater' at the head end'than at the tail end of the valve.

'The space between the main part ,of the rod and the valve stem is greater than that required to allow for relative thermal expension in order to reduce weight and also to cause the heat to flow directly from the vhottest part of the valve, its head, to the coolest part, its foot, without appreciable influence from the intermediate parts of the valve stem. With such an arrangement, a greater equalization of heat is obtained than would be ossilble otherwise, thereby restrict' in the lia ility to warpage and the like.

n making this form of construction the lower end of the valve is bored out to the maximum diameter of the stem bore and threaded internally. Next the copper` tube 7 is inserted and tinally a steel sleeve or plug is screwed intothe valve stem to produce the restricted part 9. This sleeve is bored to receive the lower end of the copper rod 3 and threaded for the reception of the screw plug 10. k

After` the rod 3 has been inserted, a screw plug 10 is inserted to close the interior of the valve. The usual hardened steel tip is then inserted when the valve is ready ior use.

Longitudinal 'diiiferential expansion is provided tor in forms shown inFigures l to 3 inclusive by making the length ci the bore of the stem somewhatgreater than the length of the rod 3,.

ln the construction shown in Figure 4l, a

-diferent method of allowing for longitudinal ditlerential expansion is shown. ln this case,

v the copper rod 11 is hrazed to the upper or head end of the bore of the stem at 12. The lower or tail end of the .rod l1 is passed through a plug 13 adapted to t the lower end of the bore of the stem. After the rod 1i -and plug 18 have been inserted, these parts are lorazed at 1d to the tail end ofthe stem., The usual hardened steel tip lois then in- .serted In Figures 5 andjti, alternative means torrlihe exterior of the valve is then turned to the desired form and size;

ln Figure 6, a threaded plug 17 is employed to which the lower end of the rod 18 is hrazed at 19.

l am aware that many 'changes may be made, and numerous details of construction may be varied through a wide range without departing from the principles of this invention, and l therefore do not purpose limiting the patent granted hereon, otherwise than necessitated by the prior art.

I claim as my invention:

l. A valve for internal combustion engines comprising a head, a stem, and a member wholly enclosed within the stem of material havinga greater heat conductivity than the stem.

2. A valve for internal combustion engines as in claim 1 in which the member consists.

chiefly of copper.

3. A valve for internal combustion engines comprising a head and a hollow stem, and a rod wholly enclosed within said stem having heat transferring contact at one end with the valve head and at the other end with the tail of the valve stem, said rod. being formed of material having a greater heat conductivity than the stem. l

d. A valvetor internal combustion engines comprising a head, a hollow stem and a member wholly enclosed within the stem of material having greater heat conductivity than the stem, the parts being so proportioned that the heat conductivity of the stem and member is greater and the combined weight is less ythan that of the stem if solid.

5. A valve for` internal combustionengines comprisin a head and hollow stem and a member o higher heat conductivity than. said stem arranged within said stem adapted to contact wit said stem adjacent its ends only thereby transferring heat directly from the valve head to the foot of the stem.

. 6. A valve for internal combustion engines comprising` a head and hollow stem and a member o higher heat conductivity than said stem arranged within said stem adapted to cpntact loosely with said stem adjacent its ends `only thereby transferring heat directly from the valve head to the foot of the stem.

I f lin testimony whereof l have hereunto suby, scribed my4 name at Cleveland, Cuyahoga County, Ohio.

- 'RICHARD E. BISSELL. 

